The Difference between String and StringBuilder in C#

Open Source Your Knowledge, Become a Contributor

Understanding the difference between the String type and StringBuilder class is really important particularly when you have a massive number of Strings (thousands or millions) to be assigned within a loop.

If you do a normal string concatenation in such long loops you will end up in a performance issue and will wreak havoc in your application, especially when you have a low-resource hosting or your application is running on your client’s machine, and you never know and can never tell what are the machine specs on which your app will be running.

It is always crucial to make sure your coding is ideally optimized and properly tested in terms of memory and CPU consumption.

In this article, I will be explaining the difference between using String and StringBuilder when dealing with your string values. and in which cases you should never use String. and other cases where StringBuilder is not the optimal solution.

To give you a proper performance difference, I will be showcasing you a performance bench-marking between the usage of String and StringBuilder when looping over a huge list of strings and concatenating the looped values. And finally I will provide you the equation to calculate the memory usage of your string and other built-in methods to do this calculation for you.